Under general anaesthesia, the heart is accessed using a full or partial sternotomy, and the person is established on cardiopulmonary bypass. The heart is stopped with cardioplegic arrest. A section of the pericardium is removed and excess adipose tissue removed. The section of pericardium is treated with glutaraldehyde and rinsed with saline to avoid drying. The aorta is opened, the valve is inspected and the diseased valve cusps carefully removed. The intercommissural distances are measured using Ozaki sizers, and the treated pericardium is trimmed to the desired size and stitched to the aortic annulus to replace the removed valve leaflet(s). When aligned, the leaflets are stitched to the wall of the aorta to create a functional valve. The aorta is closed, the heart is de-aired and cardiopulmonary bypass is stopped. The circulation is restored and the chest is closed. The function of the valve is assessed intraoperatively by transoesophageal echocardiography.